Speeding up inserts using Linq-To-Sql - Part 2

The latest post in this serie can be found at

Speeding up inserts using Linq-To-Entities - Part 4

Part one is found at http://blog.tanneryd.com/2011/11/speeding-up-inserts-using-linq-to-sql.html.

This version works better if you have nullable columns in your table and it also handles foreign keys. I.e. it will ignore foreign key objects but it requires that you set the foreign key id instead.

    partial class MyDataContext
    {
        partial void OnCreated()
        {
            CommandTimeout = 5 * 60;
        }

        public void BulkInsertAll<T>(IEnumerable<T> entities)
        {
            entities = entities.ToArray();

            string cs = Connection.ConnectionString;
            var conn = new SqlConnection(cs);
            conn.Open();

            Type t = typeof(T);

            var tableAttribute = (TableAttribute)t.GetCustomAttributes(typeof(TableAttribute), false).Single();
            var bulkCopy = new SqlBulkCopy(conn) { DestinationTableName = tableAttribute.Name };

            var properties = t.GetProperties().Where(EventTypeFilter).ToArray();
            var table = new DataTable();
            
            foreach (var property in properties)
            {
                Type propertyType = property.PropertyType;
                if (propertyType.IsGenericType &&
                    propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
                {
                    propertyType = Nullable.GetUnderlyingType(propertyType);
                }

                table.Columns.Add(new DataColumn(property.Name, propertyType));
            }

            foreach (var entity in entities)
            {
                table.Rows.Add(properties.Select(property => GetPropertyValue(property.GetValue(entity, null))).ToArray());
            }

            bulkCopy.WriteToServer(table);
            conn.Close();
        }

        private bool EventTypeFilter(System.Reflection.PropertyInfo p)
        {
            var attribute = Attribute.GetCustomAttribute(p, typeof (AssociationAttribute)) as AssociationAttribute;

            if (attribute == null) return true;
            if (attribute.IsForeignKey == false) return true; 
            
            return false;
        }

        private object GetPropertyValue(object o)
        {
            if (o == null)
                return DBNull.Value;
            return o;
        }
    }